1. Field of the Invention
This invention relates to a compliance apparatus of a robot hand which reduces the deviation in taking-up force caused by the positional deviation between an inserting part and an inserted part and enables high accuracy assembly.
2. Related Background Art
Appartuses as shown in FIGS. 1 and 2 of the accompanying drawings have heretofore been used as an apparatus for fitting an inserting part into an inserted part. In FIG. 1, reference numeral 52 designates a robot hand, reference numeral 53 denotes an inserting part, reference numeral 61 designates a flexible member such as rubber, and reference numeral 71 denotes a movable plate supported by the flexible member 61. If rubber or the like is employed as the flexible member 61 as shown in FIG. 1, a great force is required for the movement of the movable plate 71 from the viewpoints of material and structure and during no-load (the state before the inserting part fits to the inserted part), the movable plate 71 does not return to a predetermined position (the hand position), and this has led to poor self-return accuracy.
In FIG. 2, reference numeral 62 designates a flexible member such as a spring which biases a fixed plate 63 from the circumference thereof to thereby determine the position of a movable plate 64. In the method of positioning the movable plate 64 which uses the biasing force of a spring or the like as in FIG. 2, the position of the movable plate 64 is determined by the balance of the spring and is therefore greatly affected by the friction of the slide mechanism of the movable plate 64 and it is difficult to construct the parts of materials identical in spring constant, and this has also led to poor self-return accuracy as in the apparatus shown in FIG. 1.
Thus, in the conventional apparatuses, a great force is required to take up the positional deviation between the inserting part and the inserted part, and the amount of deviation to be taken up is great and during the insertion of parts, a load greater than necessary is applied to the parts, and this has led to a problem that the parts are injured and abrasion powder is produced. Further, the positioning of the movable plate has been effected by only a flexible member such as rubber or a spring and this has caused vibration of the robot hand, which in turn has led to a problem that it is difficult to move the robot arm at a high speed.